201016423 六、發明說明： (- 【發明所屬之技術領域】 本發明係關於-種將半導體材料複合棒同時切割為多個晶圓之 方法。 【先前技術】 通常利用一線錯將一半導體材料工件切割成晶圓。在先前技術 中係於-次加工操料，利用線簡半導體材料（例如梦）之圓 柱形單晶或多晶工件同時切割成多個晶圓。在這種情況下，線鑛 之處理量對於此方法之經濟可行性而言非常地重要。 由於其生產方式，於晶圓生產中會獲得較短及較長之棒件。為 了例如研究晶體«，往往必須自—單晶切㈣料分4 了增 加鋸割這些不同棒長度時之處理量，於是將多個卫㈣時夹在該 線鋸中，並於一次加工操作中切割。 US6U9673描述多個圓柱工件之同時切割，其係一個接一個同 軸配置。為此目的’係利用一常見之線鋸及分別黏合連結在一鋸 帶^之多個工件，該等碍係同轴配置，以特定間距㈣在—普 通安裝板上，藉此將它們夾在該線鑛中並同時切割。 此產生對應於工件數量之若干晶圓封包，其仍然固定在該安裝 板上。在切割之後，將隔板鬆散地放人晶圓封包之間的空間中， 以避免混淆各個晶圓封包。201016423 VI. Description of the Invention: (- TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of simultaneously cutting a semiconductor material composite rod into a plurality of wafers. [Prior Art] A semiconductor material workpiece is usually cut by a line error. Wafer-forming. In the prior art, a secondary processing material is used, and a cylindrical single crystal or polycrystalline workpiece of a thin semiconductor material (such as a dream) is simultaneously cut into a plurality of wafers. In this case, the wire ore is The amount of processing is very important for the economic viability of this method. Due to its production method, shorter and longer rods are obtained in wafer production. In order to study, for example, crystals «, it is often necessary to self-crystal (4) Sub-division 4 Increases the processing capacity when sawing these different rod lengths, so that multiple Wei (4) times are clamped in the wire saw and cut in one machining operation. US6U9673 describes simultaneous cutting of multiple cylindrical workpieces, One by one coaxial configuration. For this purpose, a common wire saw is used and bonded to a plurality of workpieces in a saw band, which are coaxially arranged at a specific spacing. (d) on a common mounting plate whereby they are clamped in the line and cut at the same time. This produces a number of wafer packages corresponding to the number of workpieces that are still attached to the mounting plate. After cutting, the spacers are Loosely placed in the space between the wafer packages to avoid confusion with individual wafer packages.
US 6802928 B2描述-種方法，其中係將相同截面之偽工件 (dummy pieces)黏合連結至待切割之工件端面上並與該工件一 起被切割後丢棄。此係為了防止在該工件之二個端面所獲得之晶 圓在切割之最後階段散開，並因而改善晶圓之幾何形狀。該方Z 4 201016423 具有嚴重之缺點，即受該_之尺寸舰歡組（柳^長 度的-部分來切割“未使用”之偽工件。另外，偽工件之提供: 操作、以及黏合連結係非常複雜且難以控制。 在US 6119673所描述之以—線_時切割多個卫件卜由於待 切割之該等工件因其製造方式而具有不同長度，因此亦無法最理 想地利用該線鋸之組長度。因為已知之晶體拉伸過程僅容許节曰 體之特定可用長度，或者因為㈣關該晶體並在該晶體 位置上產生試樣，以監測上述之㈣㈣過程，因此此問題尤其 疋在每當邊等工件係由單晶半導體材料所構成時產生。 DE 1〇2 __ 330揭露—種利用—線鑛同時將至少二個圓柱 工件切割為多個晶81之方其中係自卫件庫存巾選擇二或更多 個工件，將它們-個接-個地固定在—安襄板上，分別在該等工 件之間保持-特定最小距離’將該等工件夾在該祕中，並利用 該線錯垂直㈣等讀之縱軸（幾何轴）㈣。此方法能夠更佳 地利用線組長度。為避免混淆，類似us 6119673中描述之方法， ©在該等晶圓封包之間侧向地插人隔片，然後固定在晶圓載體上。 該等隔片可同時保護該等晶圓封包，避免橫向地向外傾斜。 所有已知方法之共同特徵為於該等棒件之間保持一距離，供切 割該等棒件。 在上述方法中，已發現到與自—對應長度之單半導體棒所切割 之晶圓相比’自-特定長度之棒騎割並以此方式所組裝之晶圓 發生幾何形狀變化。即使當合成棒與單棒等長及所使用之線組因 而相同時，亦可觀察到這種情況。 除厚度變化（TTV，GBIR)外，半導體晶圓之二個表面的平整 5 201016423 度也相當重要。在利用一線鋸切割一半導體單晶（例如一矽單晶） 之後，所產生之該晶圓具有一起伏的表面。在後續步驟中，例如 研磨或精磨（lapping)，此波紋係可根據波紋之波長與波幅及材料 移除之深度，部分或全部地去除。在最壞的情況下，此種可具有 自數毫米至例如50毫米之週期性的表面不勻度（“起伏 (undulations) ” 、“波紋（waviness) ”）’即使在對完成之半 導體晶圓拋光後，仍然可被檢測到，其對局部幾何形狀具有負面 影響。 已發現先前技術之已知方法的缺點，對於弓形及翹曲之參數影 響特別地顯著，弓形及翹曲為實際晶圓形狀與所欲之理想晶圓形 狀（或“sori”）之間偏差的測量結果，此尤其是關於晶圓之翹曲。 翹曲係定義於SEMI標準M1-1105中，其表示一晶圓之平面相對 於一該晶圓背面之基準平面之最小及最大偏差的差異。簡單地 說，該翹曲即表示該晶圓之形變測量。 【發明内容】 因此，本發明之一目的即為避免如此幾何偏差，特別是改善自 該複合棒所製造之晶圓的翹•曲。 本發明人已發現到，先前技術中之這些幾何偏差係由該等棒件 之間距所導致之技術加工變化所引起。 該目的係藉由一種利用一線鋸將一半導體材料複合棒同時切割 為多個晶圓之方法所達成，該方法係包括如下步驟： a) 自工件庫存中選擇至少二個自一或多個半導體棒所切割下 來之工件； b) 研磨每一工件之二個端面之至少一者； 201016423 C)將該至少二個工件於其經研磨之端面上，利用緊固裝置黏合 在一起，以產生一複合棒，並沿縱向將該複合棒固定在一安裝板 上，由於位於該等工件間之該緊固裝置，該等工件之間僅分別具 有一距離； d) 將其上固定有該複合棒之該安裝板夾在該線鋸中；以及 e) 利用該線鋸垂直於該複合棒之縱軸切割該複合棒。 【實施方式】 步驟a)中之工件切割，較佳係利用一線鋸實施。利用一内孔鋸 ®同樣適合。 步驟c)中所使用之該緊固裝置較佳為一黏合劑。 研磨該等端面，使得該黏合結合在一起之至少二個工件之二個 端面為平面-平行，讓該二個工件之間的黏合接頭作得盡可能的 小〇 較佳地，僅將來自同一半導體棒的之相鄰之工件位的工件黏合 在一起。因此，該二個工件較佳地係具有相同之晶體規格（如缺 Q 陷性質、摻雜等）。 較佳地，將二個工件恰好地黏合在一起。 此外，較佳於排齊拉伸邊緣（pulling edges )(使它們齊平）時， 將該等工件黏合在一起。 黏合在一起之該工件之總長度較佳係小於或等於380毫米。 較佳係使用一雙成分黏合劑作為黏合劑。例如，來自Huntsman Advanced Materials之Araldite牌高效能雙成分黏合劑係適用於 此。 最後，利用一線狀鋸將該複合棒切割成晶圓。該線鋸鋸割步驟 7 201016423 本身係根據先前技術所貫施。 在線鋸鋸割步驟之前，較佳地將該複合棒磨圓。然而，同樣較 佳地，該等工件係於組裝形成該複合棒之前已經磨圓。 當將一單晶體鋸割為個別工件時，傳統上係切割至幾何軸。然 而，接下來，傳統上係平行於晶軸將該個別之工件（在定向之後） 磨圓。幾何軸與晶轴之間的差異導致端面之對應傾斜，其係藉由 該端面之對應直角化研磨來校正。 對於先前居於該單晶體中之相鄰位置之工件之情況又不同。於 此，同樣可以想到且較佳係避免研磨端面，且對該等工件而言係 在將其磨圓之前組裝成一複合棒，即在該複合棒中將該等工件磨 圓。 不利用隔片而將工件組裝形成一複合棒隨後鋸割，因為該線鋸 之使用得到進一步改善，故與先前技術相比具有一更高之經濟可 行性。 另一方面，在鋸割過程中，根據本發明之該複合棒表現得類似 一單棒。可避免於先前技術中所觀察到之幾何偏差。 較佳地，係詳細地採取以下流程： a) 首先，將利用一帶鋸自一晶體所切割且長度可能不同之工件 磨圓。 在磨圓之後，以相對於晶軸及定向裝置所設定之一規定角度， 研磨該工件之端面。然後使該工件之二個端面精確地相互平行； b) 儲存以此方式所製備之工件，並可用於一組裝規劃系統。該 規劃系統係確定以最大限度利用該組長度之理想配置，並為製備 一複合棒建議此配置； 201016423 ο準備將所選擇之工件進行齡：g卩清潔要黏合之位置，以一 規定之層厚度施用黏合劑（例如利用—有鑛齒之抹刀），利用一黏 合裝置排齊、組裝、以及使封包固定平齊，黏合並固定該鑛帶， 且最後固化黏合劑； d) 利用該線鋸鋸割該複合棒； e) 偵測黏合位置，_齡劑並相鱗棒4 了材料識別之 目的，該等工件較佳地於其側面上具有一對應標記。 實施例 ® A 了盡可能有效率地利用線鑛中之線組長度，將二個工件（源 自同-半導體棒）黏合在一起並藉由線鋸鋸割以“晶圓化 (wafered)"，即切割為晶圓。 為此目的，將一處於未磨圓狀態下之石夕工件錯割為二個長度分 別為97毫米及91毫米之工件。利用細―公司之雙成分黏合 劑在端面上將二個工件黏合在一起，並與正確之拉伸邊緣（pumng edges)排齊。 〇 隨後將該“複合棒”磨圓，並利用一辞線之線鋸鋸割為晶圓， 並進行全面分析。 這種情況之優點為所使用之Araldite牌之雙成分黏合劑可被雜 透。在此實施例中，該二個工件之棒排列方向為相同。 實質上，該等工件係自工件庫存中所選擇，其長度可能不同， 因此係最理想地利用該線鋸之組長度。由於並未使用隔片，該等 組裝工件之間的黏合接頭係最小的，因此更佳地利用該線鋸之能 力，與先前技術相較，該方法之產量更進一步提高。 在根據本發明方法中可使用習知線鋸。這些線鋸之基本元件係 9 201016423 包括一機架、一前向饋送裝置以及一鋸割工具，該鋸割工具係由 一組平行線部所組成。一般係將該工件固定在一安裝板上並與其 一起夾在該線鋸中。 通常，係由多個平行線部形成線鋸之線組，其係在至少二個（任 選地，甚至為三、四或更多個）導線輥之間被拉緊，該等導線輥 係可旋轉地固定，且至少一個導線輥係被驅動。該線部通常係屬 於單一有限長度的線，其螺旋地繞該輥系統引導該單根線，並自 一庫存輥解開，纏繞至一接收輥上。該組長度係指沿著平行於導 線輥轴且垂直於線部之方向，自開始到最後之線部所測量到之線 ® 組長度。 在鋸割過程中，該前向饋送裝置引起一該線部與該工件之相互 相反的相對運動。該前向饋送運動之結果為，於其上施加一鋸割 懸浮液之該線係透過該工件形成平行之鋸割切口。該鋸割懸浮液 也稱為漿體，其包含懸浮於液體中之硬質材料顆粒，例如碳化矽。 亦可以使用一緊密黏合硬質材料顆粒之鋸割線。於此情況中，不 需施加鋸割懸浮液，僅需供應一液冷潤滑油，其保護該線及工件 @ 避免過熱，同時將工件切屑送出切割槽外。 組裝以形成一複合棒之圓柱工件，可由一可被線鋸加工之材料 所組成，例如多晶或單晶半導體材料（例如矽）。於單晶矽之情況 中，該等工件一般係由鋸割基本圓柱形矽單晶為長度自幾釐米至 幾十釐米之晶體件所製得。晶體件之最小長度一般為5公分。該 等工件，例如由矽所構成之晶體件，通常具有非常不同的長度， 但始終具有相同的截面。術語“圓柱形（cylindrical) ”不應被解 釋為該等工件必須具有圓形截面。而是該等工件可具有任何廣義 10 201016423 之圓柱體形狀，儘管本發明較佳為應用於具有圓柱形截面之工 件。廣義之圓柱體為具有閉合之準曲線及二個平行面，即圓柱底 面之圓柱表面所圍成之幾何體。 該複合棒較佳為不直接固定在安裝板上，而是先固定在一所謂 鋸帶或鋸割支架上。一般係藉由黏合連結將工件固定在該鋸帶上。 將該安裝板及固定於其上之該複合棒夾在一線鋸中，並基本上 垂直於其縱轴地同時將其切割為晶圓。 以下將藉助圖式解釋本發明。 ® 第1圖為示意性地表示組合形成一複合棒1之二個工件11及 12、一黏合接頭2、一鋸帶3、以及一安裝板4。 利用雙成分黏合劑組裝該工件11及12以形成該複合棒1。該二 個工件黏合連結在一起之端面的製造精度，讓該黏合接頭2可選 擇得盡可能小。 將組裝成該複合棒1之工件11及12黏合至該鋸帶3上。 將包含二個工件11及12之該複合棒1與該鋸帶3 —起固定在 q 該安裝板4上，並夾在一線錯中。 表1係表示根據先前技術之組裝工件（第2欄）及根據本發明 之複合棒（第3欄）之幾何參數的各種比較值。 為每一個參數給出三個不同分位數值之三個值：於是，波紋-極 大值（Waviness_max，Wav_max) 97.7%=56.29 微米/毫米係表示 97.7%之晶圓具有56.29微米/毫米或更小之波紋-極大值等。 相較於先前技術，幾乎所有研究之參數及分位數值均發現有顯 著改善。 藉由例如一掃描電容感測器對，測定晶圓在該鋸之前向饋送方 201016423 向之幾何形狀。首先，得到前側及背側信號之差異，為了測定該 波紋度，以一長度為ίο毫米之視窗通過依此獲得之評價曲線。該 視窗内之最大偏差產生一針對該視窗中心之新值（滾動方箱過濾 (rolling boxcar filtering ))。在該晶圓上整個掃描内的最大偏差 (♦到谷（peak-to-valley, PV ))為波紋-極大值。以同樣方式測定 Waviness_in，但僅考慮初始50毫米之掃描（線鑛切割區域） (Wav_out亦類似於此）。 弓形及翹曲係代表該晶圓變形的測量結果。翹曲為整個晶圓之 中性纖維（neutral fiber)與一基準平面（三維）之最大偏差（向 ^ 上及向下）之和。 表1 測試參數（最小平均 值，均方偏差（sigma)) 比較例（先前技術） 所得複合棒（本發明） 波紋-極大值2.3% 波紋-極大值50.0% 波紋-極大值97.7% 5.13微米/毫米 12.94微米/毫米 56.29微米/毫米 2.80微米/毫米 7.96微米/毫米 22.73微米/毫米 Wav_in 2.3% Wav_in 50.0% Wav_in 97.7% 3.30微米/毫米 11.72微米/毫米 56.29微米/毫米 2.52微米/毫米 4.44微米/毫米 ♦ 11.89微米/毫米 Wav_out 2.3% Wav_out 50.0% Wav_out 97.7% 2.87微米/毫米 6.41微米/毫米 17.23微米/毫米 1.52微米/毫米 5.37微米/毫米 22.66微米/毫米 厚度變化 2.3% 厚度變化50.0%厚度 變化97.7% 13.19微米 16.10微米 45.28微米 11.75微米 15.84微米 25.14微米 線性形狀範圍2.3% 線性形狀範圍50.0% 線性形狀範圍97.7% 4.83微米/毫米 13.09微米/毫米 34.75微米/毫米 4.78微米/毫米 7.81微米/毫米 18.95微米/毫米 12 201016423 弓形/翹曲 2.3% -5.59微米 -3·80微米 弓形/翹曲50.0% -1.65微米 -1.64毫米 弓形/翹曲97.7% 1.96微米 0.40微米 線性形狀範圍（lineasr shape range，LSR)為一對應於該鋸之前 向饋送方向掃描之中性纖維與一基準直線（二維）之最大偏差的 和0 GBIR，也稱為TTV，係對應於總厚度變化（最大與最小厚度值 之間的差）。 ❹ 舉例言之，E+H Eichhorn+Hausmann之測量儀器]V1X 7012 (對 於被鑛割晶圓而言為一種高解析度之厚度及表面剖面測量儀）係 適合用於測定該幾何參數。 另外，對一單棒（未由個別工件所組裝）、根據本發明之複合棒、 以及根據先前技術之工件所組裝之棒（彼此分開，獨立工件），測 定一次被切割之晶圓的翹曲分佈（分位數值％相對於赵曲數值微 米）。所有棒均具有相同之長度（ 380毫米）、晶體技術規格、以及 定向（orientation )。 〇 與先前技術中所組裝之工件相比，在翹曲分佈上發現_顯著改 善。這證實在線鋸鋸割期間，根據本發明之複合棒表現得不像由 工件所組裝之單棒。 因而對於一高要求之輕曲規格的訂單而言，本發明使得可自複 合棒生產多個晶圓’其具有一較低程度之“魅曲”幾何參數的較 窄分佈。 類似地’第2圖所示為同樣針對根據先前技術之由二個工件所 組裝之棒及根據本發明之複合棒之波紋-極大值參數的分佈，該複 13 201016423 合棒同樣係由二個工件所組裝，但根據本發明，該等工件彼此間 僅隔開一緊固裝置（雙成分黏合劑）。在七批工件A及工件b之黏 合位置附近分別表示該等工件A及B之波紋-極大值。在切割之 後，一批包括依次接收在卡匣（晶圓盒）中之多個晶圓（“拆分 批（split lots) )。為每一批確定每·一個晶圓之波紋-極大值。5 所示為複合棒之該等工件A及B之間的結合位置或黏合位置。 在根據先前技術之雙棒中，在批A1及B1之間有一距離，該等 工件並未黏合在一起，而是彼此間隔一定距離黏合在一鋸帶上。 對於根據先前技術之雙棒，在批A1及B1之間發現波紋-極大值 有顯著跳動。而在根據本發明之複合棒中，在鋸割之後並未發生 此種跳動：批A1及B1之波紋度值幾乎相同’這顯示根據本發明 方法之優點。 批B7之後的批（圖中未示）顯示較高的波紋-極大值。同時解 釋表1中所示之較高之分位數值。然而’此種波紋度之上升同樣 發生在單棒中，且並非本發明之範圍所關注之焦點。第2圖僅關 於工件A及工件B之過渡區域中的波紋度曲線。 因而對於一高要求之波紋度規格的訂單而言，本發明使得可自 複合棒生產多個晶圓，其具有一相對窄分佈之“波紋度，，參數（參 見表1)，尤其是避免先前技術中在組裝工件之結合位置區域所觀 察到之跳動，如第2圖所示。 【圖式簡單說明】 第1圖所示為本發明之複合棒；以及 第2圖所示為根據先前技術由二個工件所組襞之棒及根據本發 明之複合棒之波紋-極大值參數的分佈。 201016423 【主要元件符號說明】 1 複合棒 11 工件 12 工件 2 黏合接頭 3 鋸帶 4 安裝板 ❿ 15No. 6,802,928 B2 describes a method in which dummy pieces of the same cross-section are bonded to the end faces of the workpiece to be cut and are discarded after being cut together with the workpiece. This is to prevent the crystals obtained at the two end faces of the workpiece from being scattered at the final stage of the cutting, and thus to improve the geometry of the wafer. The party Z 4 201016423 has serious shortcomings, that is, it is subject to the "unused" pseudo-workpiece of the size of the ship's group (the length of the willow). In addition, the provision of the pseudo-workpiece: operation, and the bonding system is very It is complicated and difficult to control. The cutting of a plurality of guards with a line as described in US Pat. No. 6,119,673, because the workpieces to be cut have different lengths depending on the manner in which they are manufactured, it is also impossible to optimally utilize the length of the wire saw. Degree. Because the known crystal stretching process only allows the specific usable length of the knot, or because (4) closes the crystal and produces a sample at the crystal position to monitor the above (4) (4) process, this problem is particularly problematic. When the workpiece is composed of a single crystal semiconductor material, DE 1〇2 __ 330 reveals that the use of the line-mine is simultaneously cutting at least two cylindrical workpieces into a plurality of crystals 81. Or more than one workpiece, which are fixed one by one on the ampule plate, respectively, holding a specific minimum distance between the workpieces to clamp the workpieces in the secret, and using the workpiece Wrong vertical (four) read vertical axis (geometric axis) (four). This method can make better use of the length of the line group. To avoid confusion, similar to the method described in us 6119673, © laterally insert between the wafer packages The human spacers are then attached to the wafer carrier. The spacers simultaneously protect the wafer packages from laterally outward tilting. A common feature of all known methods is to maintain a distance between the members. For cutting the rods. In the above method, it has been found that the wafers assembled in this manner are self-specific length rods compared to wafers cut from a single semiconductor rod of corresponding length. A change in geometry occurs. This can be observed even when the composite rod is the same length as the single rod and the line set used. In addition to the thickness variation (TTV, GBIR), the two surfaces of the semiconductor wafer Leveling 5 201016423 is also very important. After cutting a semiconductor single crystal (for example, a single crystal) with a wire saw, the resulting wafer has a surface that is volt together. In subsequent steps, such as grinding or fine grinding (lapping) ), The corrugation may be partially or completely removed depending on the wavelength of the corrugation and the amplitude of the wave and material removal. In the worst case, such a surface unevenness may be periodic from a few millimeters to, for example, 50 millimeters ( "undulations", "waviness") can be detected even after polishing of a finished semiconductor wafer, which has a negative impact on local geometry. Methods known in the prior art have been found. Disadvantages, the effects on bow and warp parameters are particularly pronounced. Bow and warp are measurements of the deviation between the actual wafer shape and the desired wafer shape (or "sori"), especially with respect to wafers. Warpage. Warpage is defined in SEMI Standard M1-1105, which represents the difference between the minimum and maximum deviation of the plane of a wafer relative to the reference plane of the backside of the wafer. Simply stated, the warp represents the deformation measurement of the wafer. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to avoid such geometric variations, and in particular to improve the warpage of wafers fabricated from the composite rod. The inventors have discovered that these geometrical deviations in the prior art are caused by technical processing variations caused by the distance between the bars. The object is achieved by a method for simultaneously cutting a semiconductor material composite rod into a plurality of wafers by using a wire saw, the method comprising the following steps: a) selecting at least two from one or more semiconductors from the workpiece inventory a workpiece cut by the rod; b) grinding at least one of the two end faces of each workpiece; 201016423 C) bonding the at least two workpieces to the ground end faces thereof by means of fastening means to produce a a composite rod, and the composite rod is fixed to a mounting plate in a longitudinal direction, and the workpieces have only one distance between them due to the fastening device between the workpieces; d) the composite rod is fixed thereon The mounting plate is clamped in the wire saw; and e) the composite bar is cut perpendicular to the longitudinal axis of the composite bar using the wire saw. [Embodiment] The cutting of the workpiece in the step a) is preferably carried out using a wire saw. Using a bore saw ® is equally suitable. The fastening means used in step c) is preferably a binder. Grinding the end faces such that the two end faces of the at least two workpieces bonded together are planar-parallel, so that the adhesive joint between the two workpieces is made as small as possible, preferably only from the same The workpieces of adjacent workpiece bits of the semiconductor rod are bonded together. Therefore, the two workpieces preferably have the same crystal size (e.g., lack of Q trapping properties, doping, etc.). Preferably, the two workpieces are just glued together. Moreover, it is preferred to bond the workpieces together when the pulling edges are aligned (to make them flush). The total length of the workpiece bonded together is preferably less than or equal to 380 mm. It is preferred to use a two-component adhesive as a binder. For example, the Araldite high performance two-component adhesive from Huntsman Advanced Materials is suitable for this. Finally, the composite rod is cut into wafers using a wire saw. The wire saw sawing step 7 201016423 itself is performed according to the prior art. Preferably, the composite rod is rounded prior to the wire sawing step. However, it is also preferred that the workpieces are rounded prior to assembly to form the composite rod. When a single crystal saw is cut into individual workpieces, it is conventionally cut to the geometric axis. However, next, the individual workpieces (after orientation) are conventionally rounded parallel to the crystal axis. The difference between the geometric axis and the crystal axis results in a corresponding tilt of the end face, which is corrected by the corresponding right angled grinding of the end face. The situation is different for workpieces that were previously in adjacent positions in the single crystal. Accordingly, it is also conceivable and preferred to avoid grinding the end faces, and the workpieces are assembled into a composite rod prior to rounding it, i.e., the workpieces are rounded in the composite rod. The workpiece is assembled without using a spacer to form a composite rod and then sawed, since the use of the wire saw is further improved, resulting in a higher economic viability than the prior art. On the other hand, the composite rod according to the present invention behaves like a single rod during the sawing process. Geometric deviations observed in the prior art can be avoided. Preferably, the following procedure is taken in detail: a) First, a workpiece cut from a crystal and having a different length may be rounded using a band saw. After rounding, the end faces of the workpiece are ground at an angle specified by one of the crystal axis and the orientation device. The two end faces of the workpiece are then precisely parallel to each other; b) the workpiece prepared in this manner is stored and used in an assembly planning system. The planning system is optimized to maximize the ideal length of the set and is recommended for the preparation of a composite rod; 201016423 ο Prepare the selected workpiece for age: g卩 clean the position to be bonded, to a defined layer Thickness application adhesive (for example, using a spatula with a tooth), aligning, assembling, and fixing the package with a bonding device, bonding and fixing the tape, and finally curing the adhesive; d) using the wire The saw is cut by the saw; e) detecting the bonding position, the ageing agent and the scale bar 4 have the purpose of material identification, and the workpieces preferably have a corresponding mark on the side thereof. Example ® A utilizes the length of the wire group in the wire ore as efficiently as possible, bonding two workpieces (derived from the same-semiconductor rod) together and sawing by wire sawing to "wafered" , that is, cutting into wafers. For this purpose, a stone-like workpiece in an unrounded state is miscut into two workpieces of lengths of 97 mm and 91 mm, respectively. The two workpieces are bonded together on the end face and aligned with the correct pumng edges. 〇 The "composite rod" is then rounded and sawn into a wafer using a line saw. A comprehensive analysis is performed. The advantage of this case is that the Araldite brand two-component adhesive used can be miscible. In this embodiment, the rods of the two workpieces are arranged in the same direction. In essence, the workpieces are self-contained. The length of the workpiece stock may be different, so the length of the wire saw is optimally utilized. Since the spacer is not used, the bonding joint between the assembled workpieces is the smallest, so it is better to use the Wire saw ability, and previous skills In comparison, the throughput of the method is further improved. Conventional wire saws can be used in the method according to the invention. The basic component of these wire saws 9 201016423 comprises a frame, a forward feed device and a sawing tool, The sawing tool is composed of a set of parallel wire portions. Generally, the workpiece is fixed on a mounting plate and clamped together in the wire saw. Generally, a wire saw is formed by a plurality of parallel wire portions. It is tensioned between at least two (optionally even three, four or more) wire rolls that are rotatably fixed and at least one wire roll is driven. The portion is typically a single finite length wire that is helically guided around the roller system and unwound from a stock roll and wound onto a take-up roll. The length of the set is along the axis parallel to the wire. And perpendicular to the direction of the line portion, the length of the line group measured from the beginning to the last line portion. During the sawing process, the forward feeding device causes a relative movement of the line portion and the workpiece opposite to each other. The forward feed motion The wire on which the sawing suspension is applied passes through the workpiece to form parallel saw cuts. The sawing suspension, also referred to as a slurry, contains particles of hard material suspended in a liquid, such as carbonization.锯. It is also possible to use a sawing line that closely bonds the hard material particles. In this case, it is not necessary to apply a sawing suspension, only a liquid cold lubricating oil is required, which protects the wire and the workpiece @ to avoid overheating and at the same time The chips are fed out of the cutting groove. The cylindrical workpiece assembled to form a composite rod may be composed of a material that can be processed by a wire saw, such as a polycrystalline or single crystal semiconductor material (for example, tantalum). In the case of a single crystal crucible, The workpiece is generally made by sawing a substantially cylindrical 矽 single crystal as a crystal piece having a length of a few centimeters to several tens of centimeters. The minimum length of the crystal piece is generally 5 cm. The workpieces are, for example, crystals composed of ruthenium. Pieces, usually of very different lengths, but always have the same cross section. The term "cylindrical" should not be interpreted to mean that the workpieces must have a circular cross section. Rather, the workpieces can have any cylindrical shape of the generalized 10 201016423, although the invention is preferably applied to workpieces having a cylindrical cross section. The generalized cylinder is a geometry surrounded by a closed quasi-curve and two parallel faces, that is, the cylindrical surface of the cylindrical bottom. Preferably, the composite rod is not directly attached to the mounting plate, but is first secured to a so-called saw band or sawing bracket. The workpiece is typically secured to the saw band by an adhesive bond. The mounting plate and the composite rod affixed thereto are clamped in a wire saw and simultaneously cut into wafers substantially perpendicular to its longitudinal axis. The invention will be explained below by means of the drawings. ® Fig. 1 is a view schematically showing two workpieces 11 and 12 which are combined to form a composite rod 1, an adhesive joint 2, a saw belt 3, and a mounting plate 4. The workpieces 11 and 12 are assembled using a two-component adhesive to form the composite rod 1. The manufacturing precision of the end faces of the two workpieces bonded together allows the bonding joint 2 to be selected as small as possible. The workpieces 11 and 12 assembled into the composite rod 1 are bonded to the saw band 3. The composite rod 1 including the two workpieces 11 and 12 is fixed to the mounting plate 4 together with the saw tape 3, and is sandwiched in a line error. Table 1 shows various comparison values of the geometric parameters of the assembled workpiece (column 2) according to the prior art and the composite rod (column 3) according to the present invention. Three values for three different quantile values are given for each parameter: then, the ripple-maximum value (Waviness_max, Wav_max) 97.7% = 56.29 microns/mm means that 97.7% of the wafers have 56.29 microns/mm or less. Ripple - maximum value, etc. Significant improvements were found in almost all of the study parameters and quantile values compared to the prior art. The geometry of the wafer to the feed side 201016423 is determined prior to the saw by, for example, a scanning capacitive sensor pair. First, the difference between the front side and the back side signals is obtained. To determine the waviness, the evaluation curve obtained by this is obtained by a window having a length of ίο mm. The maximum deviation within the window produces a new value for the window center (rolling boxcar filtering). The maximum deviation (peak-to-valley, PV) over the entire scan on the wafer is the ripple-maximum value. Waviness_in is measured in the same way, but only the initial 50 mm scan (line cut area) is considered (Wav_out is similar). The bow and warp represent the measurement of the deformation of the wafer. Warpage is the sum of the maximum deviation (upward and downward) of the neutral fiber of the entire wafer from a reference plane (three-dimensional). Table 1 Test parameters (minimum mean, mean square deviation (sigma)) Comparative Example (Prior Art) Composite rod obtained (invention) Corrugation - maximum value 2.3% ripple - maximum value 50.0% ripple - maximum value 97.7% 5.13 μm / Mm 12.94 μm/mm 56.29 μm/mm 2.80 μm/mm 7.96 μm/mm 22.73 μm/mm Wav_in 2.3% Wav_in 50.0% Wav_in 97.7% 3.30 μm/mm 11.72 μm/mm 56.29 μm/mm 2.52 μm/mm 4.44 μm/mm ♦ 11.89 μm/mm Wav_out 2.3% Wav_out 50.0% Wav_out 97.7% 2.87 μm/mm 6.41 μm/mm 17.23 μm/mm 1.52 μm/mm 5.37 μm/mm 22.66 μm/mm Thickness change 2.3% Thickness change 50.0% Thickness change 97.7% 13.19 micron 16.10 micron 45.28 micron 11.75 micron 15.84 micron 25.14 micron linear shape range 2.3% linear shape range 50.0% linear shape range 97.7% 4.83 micron / mm 13.09 micron / mm 34.75 micron / mm 4.78 micron / mm 7.81 micron / mm 18.95 micron / Mm 12 201016423 Bow/warp 2.3% -5.59 micron - 3.80 micron bow / warp 50.0% -1.65 micro -1.64 mm bow/warp 97.7% 1.96 micron 0.40 micron linear shape range (LSR) is a maximum deviation of a neutral fiber from a reference line (two-dimensional) corresponding to the saw before feeding the saw. And 0 GBIR, also known as TTV, corresponds to the total thickness change (the difference between the maximum and minimum thickness values). ❹ For example, the E+H Eichhorn+Hausmann measuring instrument] V1X 7012 (a high-resolution thickness and surface profile measuring instrument for ore-cut wafers) is suitable for determining this geometrical parameter. In addition, the warpage of the wafer to be cut is measured for a single rod (not assembled by an individual workpiece), a composite rod according to the present invention, and a rod assembled according to the prior art workpiece (separate from each other, independent workpiece). Distribution (% of the quantile value relative to the micrometer value of the Zhao Qu). All rods have the same length (380 mm), crystal specifications, and orientation.发现 Significant improvements were found in the warpage distribution compared to the workpieces assembled in the prior art. This confirms that the composite rod according to the present invention does not behave like a single rod assembled from a workpiece during wire sawing. Thus, for a demanding, lightly sized order, the present invention enables a plurality of wafers to be self-reinforcing rods that have a narrower distribution of a lower degree of "magic" geometry. Similarly, Fig. 2 shows the distribution of the ripple-maximum parameter of the rod assembled from two workpieces according to the prior art and the composite rod according to the present invention, the same 13 201016423 rod is also composed of two The workpieces are assembled, but according to the invention, the workpieces are separated from each other by only one fastening means (two-component adhesive). The ripple-maximum values of the workpieces A and B are indicated in the vicinity of the bonding positions of the seven batches of the workpiece A and the workpiece b, respectively. After dicing, the batch includes a plurality of wafers ("split lots") that are sequentially received in a cassette (a wafer cassette). The ripple-maximum value of each wafer is determined for each batch. 5 shows the bonding position or bonding position between the workpieces A and B of the composite rod. In the double rod according to the prior art, there is a distance between the batches A1 and B1, and the workpieces are not bonded together. Rather, they are bonded to each other at a distance from each other. For the double rod according to the prior art, the ripple-maximum value is found to be significantly jumped between the batches A1 and B1. In the composite rod according to the invention, in the sawing This type of bounce does not occur afterwards: the waviness values of the batches A1 and B1 are almost the same 'This shows the advantages of the method according to the invention. The batch after batch B7 (not shown) shows a higher ripple-maximum value. The higher quantile values shown in Table 1. However, the rise in such waviness also occurs in a single rod and is not the focus of the scope of the present invention. Figure 2 is only for workpiece A and workpiece B. The waviness curve in the transition zone. In terms of high demand waviness specification orders, the present invention enables the production of multiple wafers from a composite rod having a relatively narrow distribution of "waviness, parameters (see Table 1), especially to avoid prior art The bounce observed in the combined position area of the assembled workpiece is shown in Figure 2. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a composite rod of the present invention; and Fig. 2 shows a ripple-maximum parameter of a rod assembled from two workpieces according to the prior art and a composite rod according to the present invention. Distribution. 201016423 [Explanation of main component symbols] 1 Composite rod 11 Workpiece 12 Workpiece 2 Adhesive joint 3 Saw belt 4 Mounting plate ❿ 15